nvidia gtx 1080ti 11gb - $1191
nvidia gtx 1070 8gb - $641
nvidia gtx 1060 3gb - $290
nvidia gtx 1050ti - $213
nvidia gtx 1050 2gb - $152
amd rx 580 8gb - $412
amd rx 570 4gb - $400
That is a horrible price for a 1080ti 11gb. I wouldn't pay more than $750 for a 1080ti, so that's about $400 too expensive and ROI will be ridiculous for that kind of price. From that list, it looks like your best options are either RX580, or 1050TI in my opinion. I would honestly search for a better price of 1080ti's though, because that would be the card to go for if you can manage it. The price on these cards seem so arbitrary and you should probably expand your search.
Hey,
Thanks for the suggestion sir , today I checked with another seller and I can get 1080ti OC version for around $800
Buy as you said ROI will be too high.. I am thinking to get ×2 580s and save rest of the money and hold it for another 2-3 months and wait for new Nvidia GPUs to show..if I can get a hands on them otherwise will keep searching for 1080ti below $700 maybe
Actually a 1080Ti earns about as much as 2x 580, maybe slightly less. At $800 the 1080Ti is the best buy on your list. But I agree with others that now isn't a great time to buy new gpus for mining. Next generation of gpus is around the corner, and altcoin prices are relatively low.